Vitamin B12 is essential for the proper functioning of our body. Mainly found in animal products, it can be deficient in people following a vegetarian or vegan diet. What is our need for vitamin B12 and how do we get it? We’ll tell you everything you need to know about this B vitamin.
Vitamin B12, what is it?
Vitamin B12 is one of the 8 B vitamins. It represents a cobalt-based set of water-soluble molecules (which can dissolve in water), hence its name, cobalamin. It is mainly synthesized by microorganisms such as bacteria. The human body can store it in small amounts, but cannot produce it, so this vitamin must be obtained from food.
Why is this necessary?
Like many other vitamins, cobalamin is essential for our good health. It is particularly involved in the proper functioning of the nervous system and blood system. It is also essential for the normal functioning of our immune system and helps reduce fatigue and exhaustion. Finally, it contributes to normal energy metabolism. 
What is our need for vitamin B12?
The European Union recommends an adult intake of 2.5 micrograms of vitamin B12 (RPN) per day. In turn, ANSES (National Agency for Food Safety) has established an adequate intake of vitamin B12 (AS) according to age  :
- 1.5 micrograms per day (μg/d) for children aged 6 months to 10 years,
- 2.5 μg/d for adolescents aged 11 to 17 years
- 4 μg/d for adults over 18 years of age
- 4.5 μg/d for pregnant women
- 5 μg/d for lactating women
How do you know if you are deficient?
The daily requirement of vitamin B12 should be minimal and the stores high, cobalamin deficiency may be detected only after several weeks, if not longer. According to ANSES, vitamin B12 deficiency most commonly manifests as “megaloblastic anemia.” This would be accompanied by symptoms such as fatigue or shortness of breath (unpleasant and embarrassing breathing sensation), visual disturbances or even poor body protection. The list is comprehensive on the organization’s website.
If these symptoms occur, it is best to consult a health care professional who can prescribe a vitamin B12 dose to identify a possible deficiency. If necessary, he can prescribe the appropriate treatment.
Where can I find vitamin B12?
Vitamin B12 is most abundant in animal products such as offal (especially liver), fish, eggs, meat, milk and other dairy products. Therefore, vitamin B12 deficiency is especially common among vegans.
Certain fermented vegetable products and certain algae such as spirulina are often cited as natural sources of vitamin B12, but beware! Most of the time, these products contain small and insufficient amounts for our needs, or they contain molecules similar to vitamin B12, but which the body does not absorb. Therefore, they should not be considered sources of vitamin B12. 
In the case of veganism, it is necessary to supplement with vitamin B12. The same is true for people who follow a vegetarian diet and consume very few dairy products. Cobalamin can be found in tablet, capsule or ampoule form and can be purchased in organic stores, online or in pharmacies, with prices ranging from less than 3 euros to 20 euros, depending on the dose.
For effective supplementation, the French Vegetarian Association and the French Vegan Society recommend using: 
- ie 1.3 µg (microgram) three times a day
- i.e. 10 µg once daily
- ie 2000 µg once a week
- i.e. 5000 mcg once every two weeks
Whether you’re an omnivore, vegetarian or vegan, now you know all about this essential vitamin and how to get it!